Having prepped the cylinders we started installing pistons. Then notices a small pin hole in the #1 cylinder top surface. Looked like a casting inclusion that would be abel to be polished out. But as we started it got bigger and deeper. Once we where down over 0.5mm and still not at the bottom it was getting obviouss this piston wasn't going to be useable.
Also the new circlips wouldn't fit in. Got in contact with CAMIT and got everything sorted. Ian at CAMIt has been very helpful throughout. So we have the engine ready for assemble and just waiting on parts now. No hurry, plenty of other tasks remaining.